Study on photoaging of poly(p‐phenylene benzobisoxazole) fiber

Abstract

As a kind of rig-rod-like polymer, poly(pphenylene benzobisoxazole) (PBO) has received great interest because of its excellent mechanical properties and good thermal stability. The use of PBO fibers, however, is limited due to its low sunlight stability. In this work, the photoaging of PBO fibers, as well as the effects of oxygen and moisture on their photoaging, is investigated by tensile strength measurements, infrared spectroscopy, molecular mass determination, and scanning electron microscopy. It is first time to find that the photoaging of PBO fibers includes two development stages. The physical aging is the dominate factor at the first stage of photoaging relative to the second stage, in which the chemical aging is the dominate factor. In the first degradation stage, long defects appear and develop parallel to the fiber axis. Little chemical change occurs in this stage. In the second degradation stage, the molecular mass of PBO decreases and chemical degradation occurs. Oxygen accelerates the occurrence of chemical degradation. It is also found PBO fibers are more stable for photoaging when moisture and oxygen are isolated.

Improvement of interfacial shear strengths of polybenzobisoxazole fiber/epoxy resin composite by n‐TiO2 coating

“…As a class of heterocyclic polymer, poly( p ‐phenylene benzobisoxazole) (PBO) has received great interest because of its high performance, excellent mechanical properties, good thermal stability, and environmental stability 1–4. Typically, PBO fibers have been used in high strength applications, such as in body armor and ropes 5–11.…”

New disperse dyeing method of poly(p-phenylene benzobisoxazole) fiber pretreated with polyphosphoric acid

“…It can be used as reinforcement in advanced composites and has great potential applications in aerospace, the military and general industry [1][2][3]. The excellent mechanical and thermal properties and the chemical stability stem from the structure of PBO fiber, i.e., the rigid chain in the structural unit, a high level of crystallinity and a high degree of chain orientation along the fiber axis [4,5].…”

Preparation of a sub‐100 nm‐thick polyetherimide coating layer with nano‐TiO2 particles on poly(p‐phenylene benzobisoxazole) fiber surface

“…The company commercially produces two types of PBO fibers: standard‐type AS and high‐modulus‐type HM . As a new structural material, PBO fibers have low density, high strength, high modulus, good chemical resistance, and good thermal stability . Because of these favorable features, PBO fibers have great potential applications such as fiber‐reinforced composites, tendons for scientific balloon, high‐strength tethers, tension structures, and body armor …”